2009/02/28 by Richard Bouzerar, G. Bouzerar, Georges Bouzerar · 2 citations
Materials Science · Physics and Astronomy · #Condensed matter physics #Dynamic Monte Carlo method #Hamiltonian (control theory) #Hybrid Monte Carlo #Magnetic and transport properties of perovskites and related materials #Markov chain Monte Carlo #Monte Carlo method #Monte Carlo method in statistical physics #Monte Carlo molecular modeling #Physics #Physics of Superconductivity and Magnetism #Quantum Monte Carlo #Spins #Statistical physics #Statistics #ZnO doping and properties #cond-mat.dis-nn #cond-mat.str-el
paper · pdf · doi:10.1088/1367-2630/12/5/053042
published in New Journal of Physics 12(5), 053042 (IOP Publishing) · 11 figures, submitted to Phys. Rev
arxiv created 2009/06/12 · openalex publication_date 2010/05/26 · arxiv updated 2015/05/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
In this paper, we discuss the magnetic properties of dilute systems of localized spins interacting with itinerant carriers. More precisely, we compare recent available Monte Carlo (MC) results with our two-step-approach (TSA) calculations. The TSA depends first on the determination of the magnetic couplings and then on a proper treatment of the resulting effective dilute Heisenberg Hamiltonian. We show an important disagreement between the MC results (in principle exact) and our TSA calculations. We analyze the origins and shed light on the reasons for those dissensions. In contrast to what one could expect, we demonstrate that the available MC calculations suffer from severe numerical shortcomings. More precisely, (i) the finite size effects appear to be huge in dilute systems, (ii) the statistical sampling (disorder configurations) was far too small and (iii) the determination of the Curie temperature was too rough. In addition, we provide new arguments to explain a recent disagreement between the MC simulations and TSA for the model study of the well-known III–V diluted magnetic semiconductor Ga 1− x Mn x As. We hope that this work will motivate new systematic large-scale MC calculations.